Electromagnetic recoil system for a gun



.T 2 I 5175.2? /8 25 I G. R. CARLSON ETAL 2,18,783

ELECTROMAGNETIC RECOIL SYSTEM FOR A GUN Filed April 22, 1955 r INVENTOES 4 i George R.-B'E1I15EITL v- Ahmed ILKufud'nr By Esaverin -Huynur ATTORNEYS ELECTROMAGNETIC RECOILSYSTEM FOR A GUN George R. Carlson, Glencoe, Ahmed D. Kafadar, Chicago, and Severin Raynor, Winnetlra, Ill., assignors, by mesneassignmentg'to the United States'of America ;-as-represented;hy the Secretary of the Army Application April 22, 1953, Serial No. 350,402

10 Claims. (Cl. 89-42) Theinventionrelates generally to recoil mechanisms for guns. More particularly the invention relates to im- .provements in recoil mechanisms. of the type wherein electricalzenergy is utilized to produce the braking force.

;-Several factors must be considered when the eifective- .ness'of a recoil mechanism is studied. Ambient temperature for example may. prevent the usual .hydropneumatic .systemfrom operating. The system is expected to function in substantially the same manner under any combina- -.tionof climatic and terrain conditions which may be found on this earth,-whether it is an arctic blizzard at 70 -F".,. a. tropical beach with salt spray and 100 percent rela- 'tive humidity, or a desert with temperatures to +150 F. and-blowing sand. In addition to the wide range of ambient temperature over which the mechanism must perform its own temperature is raised as a result of the energy it absorbs. -Under conditions of rapid fire it is possible .toxattainea temperature of 300 F. or higher,,so .that the mechanism .is.actually-expected to give satisfactory performance over-a range of 400 F. Another limiting tactoris the vulnerability of the standard hydropneu- IHH'UCSYSRDJS to enemy smallvarms fire and small shell fragments, because a slight .dent in the cylinder wall is sufficient to cause the very rapid failure .of a packing which must ride over it.

.It is therefore. a prime object'of our invention :toeprovide a novelrecoil mechanism that is completely-effective under all operating conditions and is easy and. cheap to manufacture.

Itisa furtherobject of'our invention to provide a gun recoil'mechanism" that willsmoothly. dampen the energy .rof'reeoilwithout. damage to the gunand without change .in'roperating characteristics under conditions vof rapid fire. IItflSIBJIIIlOIfi specific object of our invention to dampen :the linear motion ofa' gun barrel using'the principle of the eddy current brake.

.In the accompanying'drawings in -which a-preferred embodiment is illustrated.

Figure l is a longitudinal section view of apparatus incorporating our invention.

Figure 2 is a cross sectiontaken on ,line,22 of Figure' land looking in the direction ofthe arrows.

Figure 3 isa cross section taken on line.33 of Figure land looking in the direction of the arrows.

Referring now more particularly to Figure 1 wherein a recoil means that functions as an eddy current brake is shown, and wherein similar reference characters indicate corresponding parts, numeral 1 indicates a gun bar- .rel ofconventional design adapted to move rearwardly upon discharge ofthe round. A spring 2 embraces the forward end of barrel land urges between housing 3 and annulus 4- which is internally threaded .to cooperate with mating threads cut into the barrel substantially as shown. An end plate 5 is secured by bolts 6 to a turned out flange on shroud '7 and carries annular rawhide buiier 8 for a purpose that will presently appear.

The eddy current brake comprises a core 13 surround- 2,81 ,783 Patented Jan. 7, 1.9.5.8

ing and secured to-barrell by'nuts l4 disposedat opposite ends thereof and carrying annular coilslS and 16 electrically connected in series. Leads 9 and Y for connecting the coils toa source of electrical energy are run through a hollow rod22 which is constrainedto .move W1th the core as will later more fully be explained. A cylinder 17 of ametalof good electrical conductivity such:as copper or,aluminum surroundscore L131, and, ex-

tends between. end plates.5.:and, 18. ,Three. tie rods, 21,

.22 and ZSaresecuredto corel3 at-their respective proximal ends and extend rearwardly therefrom. The tie; rods pierce endplate.18..with. a sliding fit. and are secured at their several distal ends to movable plate.,.24.by nutsj25.

.Three ,tie. rods .27, .28 and 1.29am, respectively threaded at their proximal .ends ,into. armature .20. andmextend rearwardly through endplate A 18 and. are secured by nuts" 24$ to .movable plate 24..whereby. the.. c0.re and armature. are .;constrained tomovetogether, with the barrel, on opposite sides of. cylinder li in recoiland. countercoil motion.

The external. surface oflhe .reCoilmechanism is formed byshroud.7nboltedor.o,thenwise,secured to plates'5 and .18 and carrying gusse ts,l9 which, bear trunnions 3% for supporting the weight of the gun.

ln operationan.electricalfi-ring circuit isprovided (not shown)-which1.contains, arelay which will not permit thegun to :fire: unlesssufiicient, current is flowing in the 'coilwindings. .Whenthe gun is fired the "barrel moves .violently backwardcarrying with it the core and armature which; as explained above, are tied together by the several-tie .rodsaud plate24and stores mechanical energy in the spring. vAs the,coreuand armature move -rear- ..wardlythe,linesofifluX, whichare shown in dottedlines in thedrawingare continuously cut by the relative motion between the core and .thecylinder. .fEddy currents are set up; in the cylindenwhich ,producefflux which interacts .with the mainfluxin the usual well known manner togive' rise to aforce which opposes the motion, andthe barrel. assembly is. braked. Whenmost of :the recoil energy has. been. dissipated ,by theeddy current brake and the remainderstored.in,,the spring the barrel assembly comes to rest.

The stored energy .in .thespringisnow usedto return the, gun tobattery. As the assembly ,moves forward the brake-again comes .into actionand thecore'finally comes to rest against the front buffer.

The rifiing torque .tending'to rotatethe" barrel is taken by the three tie rods.21, 22.-and;23..and transmitted to the trunnions through plate 18.

'We'havefound it convenient in, practice tocause Iilhe core to act-as a piston ;-in a cylinderwhereby air is..dra wn into the forward portion of the recoilwassembly ,durrng recoil, said air being partly entrapped by a one wayv valve and allowed toescapeslowly whereby the counter recoil motion is slowed.

The above described recoil structure was adapted-for use witha 37, mm.. cannon and the following values were recorded during-testing of the piece:

It will be seen from the above that the recoil means provided according to the present invention adequately absorbs the energy of recoil and counter-recoil in accordance with the objects set forth. It will be understood, of course, that the form of the invention illustrated and described herein is a preferred embodiment and that numerous modifications and alterations may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

We claim:

1. A recoil mechanism for a gun comprising a support, a gun barrel reciprocatable in recoil and counterrecoil, a. member of good electrical conductivity fixed to said support, electromagnetic flux generating means mounted adjacent said member and movable in unison with said barrel, and means for energizing said electromagnetic fiux generating means whereby relative motion between the said electromagnetic flux generating means and said member during recoil and counterrecoil produce a force to oppose said motion.

2. A recoil mechanism for a gun comprising a support, a gun barrel reciprocatable in recoil and counter- 7 recoil, a member of good electrical conductivity fixed to said support, electromagnetic flux producing means mounted for motion in unison with said gun barrel proximate to said member, and means for energizing said electromagnetic flux producing means whereby relative motion between the said electromagnetic flux producing means and said member generates a force to oppose said motion.

3. A recoil mechanism for a gun comprising a support, a gun barrel reciprocatable in recoil and counterrecoil, a member of good electrical conductivity fixed to said support, flux generating means mounted adjacent said member and movable in unison with said barrel whereby substantially all of the said fiux passes through the said member, and means for energizing said electromagnetic flux generating means whereby relative motion between said flux generating means and said member during recoil and counterrecoil produces a force to oppose said motion.

4. A recoil mechanism for a gun comprising a support,

. a gun barrel movable relative to said support in recoil and counterrecoil, a member having a length at least equal to the movement of the said gun barrel in recoil and of good electrical conductivity fixed to .said support, flux generating means mounted adjacent said member and movable in unison with said barrel whereby substantially all of the said flux passes through the said member, and means'for energizing said flux generating means whereby relative motion between said flux generating means and said member during recoil and counterrecoil produces a force to oppose said motion.

5. A recoil mechanism for a gun comprising a support, a gun barrel movable relative to saidsupport in recoil and counterrecoil, a member of good electrical conductivity and of a length at least equal to the movement of the said gun barrel in recoil fixed to said support, a magnetic circuit including a coil mounted adjacent said member "and movable in unison with said barrel, and

means for energizing said coil whereby the flux generated thereby passes through the said member and relative motion between said coil and said member during recoil and counterrecoil produces aforce to Oppose said motion.

6. A recoil mechanism for a gun comprising a support, a gun barrel movable relative to said support in recoil and counterrecoil, a cylinder of a metal of good electrical conductivity and of a length at least equal ot the movement of said gun barrel in recoil fixed to said support in concentric relation to said barrel, a magnetic circuit including a coil mounted adjacent said cylinder and movable in 111118011 with Sald barrel, and means for energizing said cell whereby the flux generated thereby passes through said magnetic circuit and a portion of said cylinder and relative motion between said coil and cylinder during recoil and counterrecoil produces a force to oppose said motion.

7. A recoil mechanism for a gun comprising a support, a gun barrel movable relative to said support in recoil and counterrecoil, a cylinder of a metal of good electrical conductivity and of a length at least equal to the movement of said gun barrel in recoil fixed to said support in concentric relation to said barrel, a magnetic circuit concentric with said barrel and including an annular coil mounted adjacent said cylinder and movable in unison with said barrel, and means for energizing said coil whereby the flux generated thereby passes through said magnetic circuit and a portion at least of said cylinder and relative motion between said coil and said magnetic circuit during recoil and counterrecoil produces a force to oppose said motion.

8. A recoil mechanism for a gun comprising a support, a gun barrel movable relative to said support in recoil and counterrecoil, a cylinder of a metal of good electrical conductivity and of a length at least equal to the movement of said gun barrel in recoil fixed to said support and surrounding said barrel, a magnetic circuit in part at least between said barrel and said cylinder and movable in unison with said barrel, a coil in said magnetic circuit, and means energizing said coil whereby the flux generated thereby passes through said magnetic circuit and a portion at least of said cylinder and relative motion between said magnetic circuit and said cylinder during recoil and counterrecoil produces a force to oppose said motion.

9. A recoil mechanism for a gun comprising a support, a gun barrelmovable relative to said support in recoil and counterrecoil, a cylinder of a metal of good electrical conductivity and of a length at least equal to the movement of said gun barrel in recoil fixed to said support concentric with said barrel, a magnetic circuit movable with said barrel and comprising a core embracing said barrel, a coil in said core and a yoke surrounding said cylinder, and means for energizing said coil whereby the flux generated thereby passes through the said cylinder and relative motion between said magnetic circuit and said cylinder during recoil and counterrecoil produces a force to oppose said motion.

10. A recoil mechanism for a gun comprising a support,

' a gun barrel reciprocable in recoil and counterrecoil, a

member of good electrical conductivity having a length at least equal to the movement of said barrel in recoil aifixed to said support, a core afiixed to and encompassing said barrel, a plurality of annular coils provided within said core adjacent said member, means for energizing said coils to produce magnetic flux thereabout, a plurality of tie rods aflixed to said core and extending rearwardly thereof coaxial with said barrel, an armature concentric with said barrel and spaced from said core by said member, a plurality of additional tie rods affixed to said armature and extending rearwardly thereof coaxial with said barrel, and a movable plate afiixed to said plurality of tie rods and to said plurality of additional tie rods, said core and armatlll'e adapted to move with said barrel in recoil and counterrecoil relative to said member to induce eddy currents within said member to provide additional magnetic flux about said eddy currents, the eddy current flux adapted to interact with said coil flux to produce a force to oppose the motion of said core and said barrel.

References Cited in the file of this patent UNITED STATES PATENTS 2,720,819 Ryan et a1 Oct. 18, 1955 FOREIGN PATENTS 22,238 Great Britain a 1894 

